What's the Formula for the Square of a Sum?

Squaring something means multiplying it by itself
'Sum' means addition
'a' and 'b' are variables
You can use this formula when you have two numbers added together and then squared
We can verify the formula by FOILing
FOILing a+b and a+b gives us the formula from above

1. Squaring something means multiplying it by itself
2. 'Sum' means addition
3. A binomial is a polynomial with two terms
1. 'a' and 'b' are variables, so they can be any number
1. 'a' and 'b' are variables, so they can be any number
1. FOIL is the method we use to multiply two binomials together
1. We can confirm that our formula is correct by squaring a+b ourselves
1. If our answer equals the right hand side when we multiply it out, we know our formula is correct
1. Multiply the first terms, a•a
2. Multiply the outer terms, a•b
3. Multiply the inner terms, b•a
4. Multiply the last terms, b•b
1. This is the right hand side of our formula!
1. Since we got the right hand side of the formula when we FOILed, we know it is correct

Formula: Square of a Sum